Update documentation and features implemented

docs/usage/index.md

@@ -0,0 +1,18 @@
+# PostgreSQL NDC Usage 
+
+This native data connector implements the following Hasura Data Domain Specification features:
+
+| Feature                                                                                                                             |    |
+|-------------------------------------------------------------------------------------------------------------------------------------|----|
+| [Simple Queries](https://hasura.io/docs/3.0/graphql-api/queries/simple-queries/)                                                    | ✅ |
+| [Nested Queries](https://hasura.io/docs/3.0/graphql-api/queries/nested-queries/)                                                    | ✅ |
+| [Query Result Sorting](https://hasura.io/docs/3.0/graphql-api/queries/sorting/)                                                     | ✅ |
+| [Query Result Pagination](https://hasura.io/docs/3.0/graphql-api/queries/pagination/)                                               | ✅ |
+| [Multiple Query Arguments](https://hasura.io/docs/3.0/graphql-api/queries/multiple-arguments/)                                      | ✅ |
+| [Multiple Queries in a Request](https://hasura.io/docs/3.0/graphql-api/queries/multiple-queries/)                                   | ✅ |
+| [Variables, Aliases, Fragments, Directives](https://hasura.io/docs/3.0/graphql-api/queries/variables-aliases-fragments-directives/) | ✅ |
+| [Query Filter: Value Comparison](https://hasura.io/docs/3.0/graphql-api/queries/filters/comparison-operators/)                      | ✅ |
+| [Query Filter: Boolean Expressions](https://hasura.io/docs/3.0/graphql-api/queries/filters/boolean-operators/)                      | ✅ |
+| [Query Filter: Text](https://hasura.io/docs/3.0/graphql-api/queries/filters/text-search-operators/)                                 | ✅ |
+| [Query Filter: Nested Objects](https://hasura.io/docs/3.0/graphql-api/queries/filters/nested-objects/)                              | ✅ |
+| [Multi-Region Routing](https://hasura.io/docs/3.0/graphql-api/queries/filters/nested-objects/)                                      | ✅ |

readme.md

@@ -31,6 +31,8 @@ If you want to report a security issue, please [read this](./docs/security.md).
 
 ## Documentation
 
+See which Hasura OpenDD Spec features are supported by the connector [here](./docs/usage/index.md).
+
 View the full documentation for the connector [here](./docs/readme.md).
 
 ### Production